The proposed studies are designed to identify and study factors of probable importance in the genesis of human urinary bladder cancer. The pathogenesis, hormonal relationships, prevention, and therapy of urinary bladder carcinomas induced in rodents by N-(4-(5-nitro-2-furyl)-2- thiazolyl) formamide will be studied in an effort to develop more understanding of this disease that may have human applicability. The bladder carcinogenicity of diazotized aromatic amines, aromatic amine analgesics, and azo dye food coloring and textile dyestuffs will be studied in mice by the pellet implantation technique and correlated with observations of the bladder carcinogenicity of these compounds administered systemically to rodents.